Atmospheric aerosol particles affect the Earth's radiative balance directly
by scattering or absorbing light, and indirectly by acting as cloud condensation
nuclei (CCN), thereby influencing the albedo and life-time of clouds. At
this time, tropospheric aerosols pose one of the largest uncertainties
in model calculations of the climate forcing due to man-made changes in
the composition of the atmosphere (IPCC, 1996). Accurately quantifying
the direct and indirect effect of anthropogenic aerosols on the radiative
forcing of climate requires an integrated research program (NRC, 1996)
that includes:

in-situ measurements covering a globally representative range of natural
and anthropogenically perturbed environments to determine the chemical,
physical, and radiative properties of the major aerosol types, the relationships
among these properties and the processes controlling them,

satellite observations to quantify the temporally and spatially varying
aerosol distributions, and

chemical transport and radiative transfer models to calculate radiative
forcing by aerosols and to provide a prognostic analysis of future radiative
forcing and climate response under various emission scenarios.

The International Global Atmospheric Chemistry Program (IGAC) has planned
a series of Aerosol Characterization Experiments (ACE) that integrate in-situ
measurements, satellite observations, and models to reduce the uncertainty
in calculations of the climate forcing due to aerosol particles. ACE-Asia
is the fourth in this series of experiments and will consist of three focused
components in the 2000-2004 timeframe:

In-situ and column integrated measurements at a network of ground stations
will
quantify the chemical, physical and radiative properties of aerosols
in the ACE-Asia study area and assess their spatial and temporal (seasonal
and inter-annual) variability (2000-2004).

An intensive field study will be used to quantify the spatial and
vertical distribution of aerosol properties, the processes controlling
their formation, evolution and fate, and the column integrated clear-sky
radiative effect of the aerosol (Late March through April, 2001).

The effect of clouds on aerosol properties and the effect of aerosols
on cloud properties (indirect aerosol effect) will be quantified in
focused intensive experiments (Spring 2001 and Spring 2002 or 2003).

ACE-Asia has been divided into three separate components so that measurement
campaigns can be carefully focused to address the goals of each component.
This structure acknowledges that the various components are in different
stages of scientific readiness and have different instrumental, sampling,
meteorological, and logistical needs. Each of the focused components of
ACE-Asia has its own Science and Implementation Plan to elaborate its goals,
research plan, needed measurements, platforms and investigators. This document
describes the overall need for an ACE-Asia experiment, the scientific goals
and objectives of the experiment as a whole, the preliminary goals of the
three components, the models that will integrate our understanding of the
climatic effect of aerosol particles, and the operational structure of
the experiment.

Further information about ACE-Asia can be found on the Project Website
(saga.pmel.noaa.gov/aceasia/) or from members of the ACE-Asia Executive
Committee:

Atmospheric aerosol particles affect the Earth's radiative balance directly
by scattering or absorbing light, and indirectly by acting as cloud condensation
nuclei (CCN), thereby influencing the albedo, life-time, extent and precipitation
of clouds. In many regions the natural aerosol has been substantially perturbed
by anthropogenic activities, particularly by increases of sulfates, nitrates,
organic condensates, soot, and soil dust. The present day global mean radiative
forcing due to anthropogenic aerosol particles is estimated to be between
-0.3 and -3.5 Wm-2, which must be compared with the present
day forcing by greenhouse gases of between +2.0 and +2.8 Wm-2(IPCC,
1996).Furthermore, the global distribution
of aerosol particles is extremely inhomogeneous due to their relatively
short lifetimes (in the range of 4-5 days, IPCC, 1996). This results
in a negative forcing that is focused in particular regions and subcontinental
areas. This uneven forcing can cause continental to hemispheric scale effects
on climate patterns.

Although aerosol particles have this potential climatic importance,
they are poorly characterized in global climate models (NRC, 1996). This
is a result of a lack of both comprehensive global data and a clear understanding
of the processes linking aerosol particles, aerosol precursor emissions,
and radiative effects. At this time, tropospheric aerosols pose the largest
uncertainty in model calculations of the climate forcing due to man-made
changes in the composition of the atmosphere. The IGAC Aerosol Characterization
Experiments (ACE) were designed to address this uncertainty and have two
overall goals:

to reduce the overall uncertainty in the calculation of climate forcing
by aerosols and,

to understand the multiphase atmospheric chemical system sufficiently to
be able to provide a prognostic analysis of future radiative forcing and
climate response.

Achieving these goals requires further development of chemical transport
models to produce accurate global aerosol distributions, clear and cloudy
sky radiative transfer models to calculate the radiative effects of aerosols,
and climate system models to study the interaction of aerosol particles
within the integrated climate system. Further developing and testing of
these models require simultaneous measurements of aerosol chemical, physical,
and radiative properties and the processes controlling those properties.
Radiative transfer models require values for aerosol optical properties
such as the light scattering efficiency per unit mass (asp),
the upward scattered fraction ()
or asymmetry factor (g), the fraction of light scattered versus that absorbed
or single scattering albedo (wo)
and the dependence of scattering by the aerosol on relative humidity (fsp(RH)).
All these properties depend in turn on the chemical composition, size distribution,
morphology and state of the mixture of the aerosol. Measurements of aerosol
chemical and physical properties, such as the mass distribution of all
chemical species, the degree of mixing of various chemical species, and
the overall size distribution, are thus needed to link global aerosol distributions
with aerosol optical properties. Improving chemical transport models requires
a quantitative understanding of precursor gas and aerosol emissions and
the processes controlling aerosol formation, transport, chemical transformation
and removal.

Measurements are clearly needed in a globally representative range of
natural and anthropogenically perturbed environments. One important region
is Eastern Asia and the Northwest Pacific. Asian aerosol sources are unlike
those in Europe and North America: much more coal and biomass are burned
(often with minimal emission controls), adding more absorbing soot and
organic aerosol to parts of the Asian and Pacific atmosphere (Chameides
et al., 1999). Economic expansion in many Asian countries will unavoidably
be accompanied by increases in fossil fuel burning. Without extensive pollution-control
measures, this will increase the amount of SO2, organic matter,
and soot emitted into the East Asian atmosphere. The presence of Eastern
Asia desert dust adds complexity, since it can both scatter sunlight back
to space (leading to a cooling effect) and absorb solar and infrared radiation
(leading to a warming effect) (Sokolik and Toon, 1999). The oxidizing environment
of the atmosphere is likely to change as the growing transportation sector
raises levels of nitrogen oxides to levels like those in Europe and North
America (van Aardenne et al., 1999). The fact that much of the Asian aerosol
then blows out over the Pacific implies that significant changes in radiative
forcing may be expected over large areas.

Aerosol optical depth over the oceans as measured by AVHRR. The red
circle shows the plume from the Asian continent that will be studied in
ACE-Asia (figure from R. Husar, Click on figure to view a larger version))

ACE-Asia will require the human and financial resources of many countries.
This international cooperation will lead to jointly developed, state-of-the-art
tools (models) and highly trained scientists in every country so that each
country can each formulate the best possible public policy regarding aerosols
and their climatic effects.

II. ACE-Asia Scientific Goals and Objectives
The goals of ACE-Asia are to determine and understand the properties and
controlling factors of the aerosol in the anthropogenically modified atmosphere
of Eastern Asia and the Northwest Pacific and to assess their relevance
for radiative forcing of climate. To achieve these goals, ACE-Asia will
pursue three specific objectives:

Objective 1. Determine the physical, chemical, and radiative properties
of the major aerosol types in the Eastern Asia and Northwest Pacific region
and investigate the relationships among these properties.

Objective 2. Quantify the interactions between aerosols and radiation in
the Eastern Asia and Northwest Pacific region

Objective 3. Quantify the physical and chemical processes controlling the
evolution of the major aerosol types and in particular of their physical,
chemical, and radiative properties.

II.1. Objective 1: Properties

The ACE approach in addressing objective 1 is two-fold. The first step
is to characterize the regional and temporal distribution of aerosol properties
in clean, polluted, and dusty airmasses. Closure experiments are used here
to validate the chemical and physical aerosol measurements and assess their
uncertainty. The second part of objective 1 investigates the relationship
between the physical, chemical, and radiative properties. Specifically,
can the measured physical and chemical properties of the aerosol be used
to predict the local and column integrated radiative properties of that
same aerosol? This approach has been used successfully in ACE-1 (Covert
et al., 1998; Huebert et al., 1998; Quinn and Coffman, 1998) and ACE-2
(Collins et al., 2000; Durkee et al., 2000; Livingston et al., 2000; Neususs
et al., 2000; Putaud et al., 2000; Russell and Heintzenberg, 2000; Schmid
et al., 2000; Welton et al., 2000) and will be a key strategy of ACE-Asia.
This strategy becomes increasing important as the complexity of the aerosol
mixture increases. ACE-1 studied a predominantly background sea-salt and
non-sea-salt (NSS) sulfate aerosol (Bates et al., 1998). The aerosol encountered
in ACE-2 included this background plus the ionic and organic aerosol from
the European continent (Raes et al., 2000). Aerosols in the ACE-Asia region
will likely be a complex mixture of sea-salt, combustion derived ionic,
organic and soot particles, mineral dust and biogenic non-sea-salt sulfate
and organic species.

II.2. Objective 2: Aerosol-Radiation Interactions

The second objective is to quantify the various impacts that aerosols
have on radiative fields in the Eastern Asia and Northwest Pacific region.
Of particular interest is the impact on radiative fluxes at a variety of
atmospheric levels (e.g., the surface, the top of the boundary layer, the
upper troposphere, the top of the atmosphere). These flux changes, when
sustained over sufficient areas and times, are the radiative forcings that
drive climate processes. In addition to sustained, extensive flux changes,
instantaneous flux change measurements are also of interest to test the
mutual consistency of measured fluxes, measured aerosol properties, and
the models that calculate flux changes from these properties. Other interactions
of interest include the effects of various types of aerosols on direct-beam
solar transmission, or optical depth, and on the radiances measured by
satellite-, aircraft- and surface-based radiometers (and hence the ability
to retrieve aerosol properties from those radiances).

II.3. Objective 3: Processes

The realism of aerosol models is limited in large part by our ignorance
of process rates. Critical processes for describing Asian aerosols include
chemical reaction rates that generate condensible species, surface exchange
processes that remove some reactants and supply others, nucleation processes
that form new particles, a suite of competing heterogeneous processes such
as coagulation, condensational growth, and wet removal that control the
size distribution, and cloud processing that promotes aqueous phase reactions.

II.4. Modeling

Mathematical models are the integrator of our understanding of atmospheric
processes. The ultimate goal of ACE-Asia is to parameterize the information
we have gained in the form of models of many types, so that the models
can be used during times and at places where observations are not possible.
Data analysis will be carried out hand-in-hand with model implementation
and evaluation: each particular experimental goal has associated with it
an appropriate physico-chemical model that serves as the test-bed for evaluating
the data obtained against our overall understanding of the atmospheric
science. Moreover, some of those models may be used prior to the experiment
in the design of the best possible measurement strategy.

The ACE-Asia region encompasses some of the most complex gas-particle
atmospheric dynamics on the Earth. Gas-phase emissions of organics, NOx,
and SO2 from the Asian continent undergo photooxidation as air
masses are advected eastward over the Pacific. Gas-to-particle conversion
occurs as condensable species are produced in the gas phase. These continental
outflows contain anthropogenically-derived particles as well as wind-blown
mineral dust. In the continental outflow region, primary aerosols of mineral
dust and sea salt origin, and the continental anthropogenic aerosols, are
transformed by gas-aerosol interactions. A key issue is the extent to which
particles of continental origin retain their source identity in the face
of gas-to-particle conversion and cloud droplet activation and evaporation.
For the first time in any global experiment the chemical evolution of mineral
dust aerosol will be assessed. It is expected that chemical processing
of mineral dust particles will be especially important in terms of its
radiative and cloud nucleating properties because of the massive anthropogenic
emissions present. Prediction of radiative properties of the evolving aerosols
requires knowledge of their size distribution and chemical composition,
the latter to be able to calculate particle refractive indices. Models
are therefore required that track both gas-phase photochemistry as well
as aerosol size and composition. Such models have only fairly recently
been developed (Pilinis and Seinfeld, 1988; Meng et al., 1998), and they
have been rigorously evaluated with ambient data only for the Los Angeles
basin.

For analysis and interpretation of ACE-Asia data models will be required
at several scales. However, there are a number of interactions between
these models: (1) Box process models will be driven with temperature and
humidity fields issued from trajectory calculations and evolving surface
emissions. (2) Radiative transfer models will be fed with aerosol profiles
from 1-D and 3-D CTMs. (3) Due to their low computational cost one-dimensional
Lagrangian CTMs may host detailed box process models. At the same time
they may be viewed as representing just one column of a global 3-D model
when hosting more simplified aerosol and chemistry models that are typically
used in 3-D CTMs. A 1-D Lagrangian CTM therefore can be used as a test-bed
to validate and improve parameterizations developed for 3-D CTMs.

It is intended to have these models formulated, tested, and running
prior to the actual intensive experiments. In the preparation of the experiment,
archived NCEP and ECMWF fields of typical ACE-Asia situations will be used
to run the 1-D Lagrangian and 3-D CTMs. During the experiment itself forecasted
meteorological fields will be used as model input to simulate likely gas
and aerosol conditions before missions are flown. Of course, actual model
runs for data evaluation can only be carried out after the experiment,
but this should greatly reduce the time needed to evaluate data after the
experiment.

III. Focused Components of ACE-Asia

The scientific goals and objectives of ACE-Asia cannot be realistically
accomplished in a single measurement campaign. Determining and understanding
the properties and controlling factors of the aerosol in the ACE-Asia region
will require measurements over a variety of time and spatial scales and
under a variety of meteorological conditions. In order to coordinate the
required investigators, platforms and instruments and maintain a scientific
focus on the goals and objectives outlined above, ACE-Asia will be organized
around three components. Each component will combine measurements of aerosol
properties and processes with models to evaluate the data obtained against
our overall understanding of the science. A brief overview of the goals
and strategies of the three components follows.

Locations of network sampling sites.

Component 1 – Network Operations

In-situ and column integrated measurements at a network of ground
stations will quantify the chemical, physical and radiative properties
of aerosols in the ACE-Asia study area and assess their spatial and
temporal (seasonal and inter-annual) variability. The goals of the characterization
studies are to:

determine the physical, chemical and radiative properties of the aerosol
in the ACE-Asia region and assess the regional and temporal (seasonal to
interannual) variability of these properties,

intercompare satellite and ground-based measurements of optical depth,
and

test and refine regional chemical transport models.

The ground station studies will be the background for ACE-Asia, providing
information on spatial variability of aerosol chemical, physical and radiative
properties and seasonal and longer-term trends in those properties. The
network data sets will be critical for planning the ACE Asia intensive
investigations and for putting those results in a broader context. In addition
to their contributions for ACE-Asia, the measurements to be made at the
ACE-Asia stations will complement ground-based studies being undertaken
for the China Metro-Agro Plex experiment (China MAP) and for the Transport
and Chemical Evolution over the Pacific experiment (TRACE-P). To the greatest
extent possible, resources will be shared among the three programs, with
coordination facilitated by APARE.

The network will focus on the outflow from Asia over the Pacific. Since
the extent of the dust impact is observed every spring as far away as the
Aleutians and North America (Jaffee et al., 1999), these should form the
northern and eastern boundaries of the network. The western boundary would
be near the Chinese deserts (the dust source regions) and the southern
boundary would be around 20-30° N, to avoid
the trade winds that deliver marine aerosols onto the continent. Two types
of stations are envisioned for the network: basic and enhanced. The basic
stations will be outfitted with a more limited set of instruments (including
one common sampler for aerosol chemical composition and various instruments
for optical and radiative studies) compared with the enhanced stations,
and typically will operate at a lower sampling frequency than the enhanced
ones. The enhanced sites will include measurements of chemical and physical
size distributions, precursor gases, and aerosol optical properties.

The overall operating plan for the network is for the science teams
from the various participating countries to purchase the sampling equipment
and as much as possible to conduct the analyses internally. Quality control
and quality assurance will be coordinated through ACE-Asia and APARE. Support
for instrumentation and analyses will be requested for situations in which
obvious scientific gaps exist or to pursue areas of research that could
make use of the network infrastructure. Information on the various network
sites can be found on the project web page.

Intensive field studies will be used to quantify the spatial
and vertical distribution of aerosol properties, the processes controlling
their formation, evolution and fate and the column integrated clear-sky
radiative effect of the aerosol. The goals of these studies are to:

determine the physical, chemical and radiative properties of the aerosol
in the ACE-Asia region and assess the vertical, regional and temporal (diurnal
to multi-day) variability of these properties,

quantify the direct radiative effect of the combined natural and anthropogenic
aerosol in the ACE-Asia study area,

refine satellite aerosol retrievals in the ACE-Asia region so that satellite
observations can be used to obtain a high temporally and spatially resolved
assessment of the clear-sky direct effect of aerosols on radiative transfer,

assess the major processes controlling the oxidation mechanisms of aerosol
precursor gases and the formation, evolution and deposition of aerosol
particles,

improve the parameterizations used in chemical transport models in order
to obtain more accurate regional distributions of aerosol properties, and

Chemical transport models (CTMs) are a critical element in aerosol radiative
forcing studies as they are the only means by which the atmospheric aerosol
can be partitioned into natural and anthropogenic components. They also
provide a prognostic capability to explore the effects of increasing or
decreasing aerosol precursor emissions on atmospheric aerosol concentrations.
To accurately calculate an atmospheric aerosol distribution, CTMs must
incorporate a quantitative parameterization of precursor gas and aerosol
emissions and the processes controlling aerosol formation, transport, chemical
transformation and removal.

The ship, aircraft, and ground-based measurements during the intensive
field operations will contribute to the regional characterization of aerosol
properties by providing data over and downwind of the continent and in
the vertical. These measurements will provide data to test and refine regional
chemical transport models. Organic, inorganic, and elemental tracers (e.g.
specific organic molecular markers of vegetation or combustion) will be
used to apportion aerosol components to different natural and anthropogenic
sources. Flight plans and ship operations will be directed to sample regional
aerosol features (e.g. dust layers, urban and industrial plumes) under
different synoptic meteorological patterns and at various distances from
shore.

Measurements of in-situ aerosol properties will form the basis for assessing
aerosol direct radiative forcing, which is defined as the change in the
global radiation balance attributable to changes in the amount of light
scattered and absorbed by particles suspended in the atmosphere. Quantifying
this forcing requires the integration of multiple measurement and modeling
approaches:

Radiative transfer models, coupled with chemical transport models, are
needed to partition the radiative effects of aerosols between the natural
and anthropogenic components and thus quantify aerosol direct radiative
forcing. These models must rely on accurate parameterizations of aerosol
properties.

Satellites are needed to assess the temporal and spatial variability
in aerosol columnar extinction. These observations can be used to assess
the direct radiative effect of the combined natural and anthropogenic aerosol.
However, the algorithms used for these retrievals must again rely on accurate
parameterizations of aerosol properties.

In-situ measurements of aerosol chemical, physical, and radiative properties
and radiative fluxes throughout the vertical column can be used to directly
quantify the radiative effect of the combined natural and anthropogenic
aerosol and provide the parameterizations needed for satellite retrievals
and models.

The combination of in-situ measurements, columnar extinction measurements
(surface-based, air and space-borne radiometers), radiative flux measurements
and models produces an overdetermined data set that can be used to evaluate
the combined uncertainty of the models and measurements used to assess
the direct radiative forcing of aerosols in the ACE-Asia study area.

Component 3 – Cloud-Aerosol Interactions

The effect of clouds on aerosol properties and the effect of aerosols
on cloud properties (indirect aerosol effect) will be studied in the
2001 intensive experiment and in a more focused experiment in 2002 or 2003.
The first campaign will focus on the interaction of aerosols with warm
clouds. The work involving mixed phase clouds will occur in the second
major campaign when developments in instrumentation and bigger aircraft
platforms may be available. The goals of the ACE-Asia cloud studies will
be to:

quantify the relationships between the physical and chemical properties
of aerosols and the microphysical and radiative properties of the clouds
that form on them,

quantify the effect of cloud processing on the aerosol properties, and

determine the relationships between aerosol properties, cloud microphysics,
the onset of precipitation and cloud lifetime in order to improve the parameterizations
used in cloud processing models, chemical transport models, and radiative
transfer models.

Clouds play an important role in the Earth’s energy balance, water cycle,
and the global cycles of many atmospheric constituents, including aerosols.
The increasing aerosol burden in the ACE-Asia region has the potential
to greatly affect cloud radiative properties, cloud distributions, cloud
lifetimes and precipitation patterns. Clouds also are one of the most important
processes controlling the aerosol size distribution and optical properties.
Although the qualitative features of this processing have been known for
years (Hoppel et al., 1990), this process is still difficult to quantify
in chemical transport models.

The dynamical nature of clouds makes it very difficult to quantify the
effect of aerosols on clouds and the effect of clouds on aerosols (cloud
processing). Addressing aerosol-cloud interactions will require several
approaches:

A hill cap cloud on Cheju Island can be used as a flow through reactor
where the reactive trace gases and the aerosol size distribution, hygroscopic
properties, and size resolved chemistry can be measured before, within,
and after a passage through cloud. (2001)

Cloudy Lagrangian studies can be performed in post cold frontal convective
cloud regions and in stable warm sector conditions to investigate the evolution
of the aerosol spectrum by cloud processing, the entrainment of aerosol
and precursor gases from the free troposphere, the role of sea-salt generated
at the ocean surface, and the formation of drizzle in the cloud. (2002
or 2003)

Cloudy column closure experiments with airborne measurements of spectrally
resolved radiation above and below cloud can be used to assess aerosol
indirect forcing. (2002 or 2003)

Frontal systems can be studied using a combination of 1 or 2 aircraft platforms
and two Doppler Radar Systems. These studies will focus on the rainbands
which are the regions responsible for much of the aerosol processing and
removal. (2001)

IV. Project and Data Management

IV.1. Management Structure

The Science Team includes all PIs participating in the project from every
country.

a representative of each major modeling effort, observing facility, and
platform, including the most comprehensive surface sites.

The SSC elected a Lead Scientist and appointed an Executive Committee to
manage the experiment. These scientists are listed in the project summary
at the beginning of this document.

IV.2. Data Policy, Protocols, and Archive

The development and maintenance of a comprehensive and accurate data
archive is a critical step in meeting the goals of the ACE. The overall
ACE data management philosophy is to make the completed data set available
to the world research community as soon as possible in order to better
incorporate aerosols into global climate models. A centralized data archive
will be established to combine the entire ACE-Asia data set. This integrated
data base will allow users a single access to the variety of measured and
derived fields obtained during ACE-Asia. A central data archive is sometimes
a difficult issue, since many groups and nations have traditionally kept
their data to themselves. However, the benefits far outweigh the liabilities
as everyone has access to a much larger data set than they could possibly
obtain or pay for alone.

The following data protocols, established for ACE 1 and 2, will hold
for all ACE-Asia participants. Listing as a participant in the Science
and Implementation Plan on the ACE-Asia web site constitutes agreement
to this data policy. Anyone not willing to abide by this policy will
not be considered a participant in ACE-Asia, and will not be given early
access to the project data prior to its public release. Obviously,
there is no benefit to making coordinated measurements if they are not
shared among the participants.

All investigators participating in ACE-Asia must agree to promptly submit
their data to the central data base to facilitate intercomparison of results,
quality control checks and inter-calibrations, and an integrated interpretation
of the combined data set.

All data shall be promptly provided to other ACE investigators upon request.
A list of ACE-Asia investigators will be maintained by the SSC and will
include the principle investigators directly participating in the field
experiment and the modellers who have provided guidance in the planning
of ACE Asia activities.

During the initial data analysis period (one year after the data were collected),
no data may be provided to a third party (journal articles, presentations,
research proposals, other investigators) without the consent of the investigator
who collected the data. This initial analysis period is designed to provide
an opportunity to quality control the combined data set.

It is the intent of the ACE science team that all data will be considered
public domain at the end of the ACE-Asia field experiment and that any
use of the data will include either acknowledgment or co-authorship at
the discretion of the investigator who collected the data.

Data that can be traced to intercompared instruments will be given a "quality-
checked" flag in the data archive. This will provide data archive users
with a "confidence level" assessment when comparing different data sets.

ACE-Asia plans to work closely with a NASA GTE experiment, TRACE-P (Transport
and Chemical Evolution over the Pacific) that is planning to study Asian
outflow to the Pacific in February and March of 2001. It will involve flights
of both NASA’s P-3 and DC-8 aircraft. The focus of TRACE-P is on photochemistry
in Asian outflow, which is complementary to the ACE-Asia aerosol-oriented
focus. We plan to coordinate some part of our flight hours and ship observations
to take advantage of the complimentary sets of instruments brought by the
two programs. We will also work closely with the APEX (Asian Particulate
Environment Change Studies) program, being organized by Prof. Nakajima.
APEX will coordinate observations during a variety of periods from 2001
through 2004.

IV.5. World Wide Web

Further information can be found on the ACE-Asia web site: http://saga.pmel.noaa.gov/aceasia/.
The web site includes the Science and Implementation plans for each component,
proposed platforms and measurements, instrument working groups, and a list
of all persons having asked to be informed about ACE- Asia.